871 mess
10-23-2021, (Subject: 871 mess ) 
Post: #1
871 mess
Built a motor for a customer that brought it to me in boxes. They tore it down 2 years ago and let it set open in their shop. It had previously spun a cam bearing. Cut the block, new bearings, pistons, liners, camshafts. Everything went together as well as can be when you go back behind someone else. Truck rolls over gets good oil to the top of the motor. Hooked the fuel back up fires easily. Good oil pressure, get the air out of the fuel system, best this truck as ever sounded and felt. 650K Miles on it. Peterbilt put 3 motors in it all under warranty this is the 6th total rebuild. #4 and 5 were done at pee dee eye so those don't really count. Upon assembly found why they spun a bearing to start with, rocker arm bolt stripped so they just put a standard thread bolt back in the hole. It stripped out also. Got that issue fixed. Drive the truck 10 miles or so runs good. No issues. Then it dies like you cut the fuel off. Plugged into it, 14 PSI fuel pressure. Slap a high pressure fuel pump on it same thing. Thought better start at the top like Carl on sling blade with with the lawn mower being out of gas. Pulled the valve cover barred the motor inj cam isn't moving Valve cam was moving as it should. Pulled the front cover, inj gear bolt was 1/2 out gear was loose on the cam. I know I tightened it to quick serve spec. 100 ft lbs plus a flat and a 1/2. Back it off and repeat. 609 on the gear. Same way I do all of em and have never had one come loose. Got to looking around aluminum shavings around the #1 cylinder. Several long strands. Put the bolt back in the cam. She's locked down. Put a breaker bar on it got it to move but its not right. Get it to come out finally, front 2 bearings are welded on the cam. We ran it with the valve cover off in the shop, everything was oiling as it should.

Now to the fun part--why?-- Aftermarket head and I'm sure the machine shop used aftermarket bearings as they warranted the last spun bearing. Bad combination? I always use a factory head so I don't know about aftermarket quality but the customer provided it. Should've known better.

Now where did the aluminum shavings come from? Bearing coating of some sort?


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Messages In This Thread
871 mess - CANNONBALL - 10-23-2021
RE: 871 mess - Nostalgic - 10-23-2021,
RE: 871 mess - CANNONBALL - 10-23-2021,
RE: 871 mess - Nostalgic - 10-23-2021,
RE: 871 mess - Rawze - 10-24-2021,
RE: 871 mess - Nostalgic - 10-24-2021,
RE: 871 mess - Rawze - 10-24-2021,
RE: 871 mess - tree98 - 10-24-2021,
RE: 871 mess - CANNONBALL - 10-24-2021,
RE: 871 mess - Rawze - 10-24-2021,
RE: 871 mess - CANNONBALL - 10-24-2021,
RE: 871 mess - Running rough - 10-24-2021,
RE: 871 mess - CANNONBALL - 10-24-2021,
RE: 871 mess - Mr Hagg - 10-25-2021,
RE: 871 mess - Rawze - 10-25-2021,



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